Device for cooling motor end-turns in a compressor

Abstract

A cooling device for a hermetic motor-compressor unit having an outer housing with a lubricant sump in the bottom thereof, a rotatable crankshaft vertically disposed in the housing, and a motor having a stator circumferentially disposed about the rotating crankshaft and a rotor connected to the crankshaft for rotation therewith. The cooling device comprises a pick-up tube connected to the rotating crankshaft and having one end thereof extending into the lubricant sump. The pick-up tube has an axial bore disposed therein and a radial passage means disposed therein in communication with the axial bore so that, upon rotation of the crankshaft, oil is pumped upwardly through the axial bore and a portion thereof thrown radially outwardly through the radial passage means and directly against the inner surfaces of the lower end turns of the stator without having first contacted any other parts of the motor.

What is claimed is: 
     
       1. In a hermetic motor-compressor unit including an outer housing having a lubricant sump in the bottom thereof, a rotatable crankshaft vertically disposed in said housing, and a motor having a stator circumferentially disposed about said rotating crankshaft and a rotor connected to said rotating crankshaft for rotation thereof, a cooling device comprising: a centrifugal lubricant pick-up tube having one end directly attached to said rotating crankshaft for rotation therewith and its opposite end extending vertically into said lubricant sump, said pick-up tube including an axial bore extending upwardly therein from said opposite end and a pump means for pumping lubricant upwardly from said sump,   said stator having lower end turns extending downwardly in said outer housing, said lower end turns having their radially inner surfaces in radially adjacent and spaced-apart relationship with said pick-up tube,   said pick-up tube having a radial passage means therein in communication with said axial bore and in direct facing relationship with said stator lower end turns for throwing a portion of lubricant pumped upwardly through said axial bore radially outwardly therethrough and directly against said radially inner surfaces of said lower end turns for the cooling thereof prior to contacting any other portions of said motor.   
     
     
       2. The unit of claim 1 wherein said lower end turns of said stator have a bottom portion thereof immersed in said lubricant sump. 
     
     
       3. The unit of claim 1 wherein the diameter of said radial passage means is less than the diameter of said axial bore. 
     
     
       4. The unit of claim 1 wherein said radial passage means comprises a hole in said pick-up tube axially below said rotor. 
     
     
       5. In a hermetic motor-compressor unit including an outer housing having a lubricant sump in the bottom thereof, a rotatable crankshaft vertically disposed in said housing, and a motor having a stator circumferentially disposed about said rotating crankshaft and a rotor connected to said rotating crankshaft for rotation thereof, a cooling device comprising: a centrifugal lubricant pick-up tube having one end directly attached to said rotating crankshaft for rotation therewith and its opposite end extending vertically into said lubricant sump, said pick-up tube having an axial bore extending upwardly therein from said opposite end and including a pump means,   said stator having lower end turns extending downwardly in said outer housing, said lower end turns having their radially inner surfaces in radially adjacent and spaced-apart relationship with said pick-up tube,   said pick-up tube having a radial passage means therein in a communication with said axial bore and positioned lower than said rotor to be in direct facing relationship with said stator lower ends turns for throwing a portion of lubricant pumped upwardly through said axial bore radially outwardly through said passage means directly against said radially inner surfaces of said lower end turns for the cooling thereof prior to contacting said rotor.   
     
     
       6. In a hermetic motor-compressing unit including an outer housing having a lubricant sump in the bottom thereof, a rotatable crankshaft vertically disposed in said housing and having an axial passage extending through one end thereof, and a motor having a stator circumferentially disposed about said rotating crankshaft and a rotor connected to said rotating crankshaft for rotation thereof, a cooling device comprising: a tubular member having opposite end portions, one of said end portions being securely fitted into said axial passage of said crankshaft one end for rotation therewith, the other said end portion being generally frusto-conically shaped for drawing oil upwardly and extending vertically into said lubricant sump, said tubular member having an axial bore extending therein from said other end portion,   said stator having lower end turns extending downwardly in said outer housing, said lower end turns having their radially inner surfaces in radially adjacent and spaced-apart relationship with said tubular member,   said tubular member having an opening radially disposed therein, said opening being in communication with said axial bore and positioned lower than said rotor to be in direct facing relationship with said stator lower end turns for throwing a portion of lubricant pumped upwardly through said axial bore radially outwardly through said opening directly against said radially inner surface of said lower end turns for the cooling thereof prior to contacting said rotor.